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Set-up of Sestos PID controller

Set-up of Sestos PID controller

(OP)
Hi,

I intend to use Sestos PID temperature controller D1S-VR-220.
Sensor is connected to 220V power supply.
The controller receives output from immersion temperature probe:
http://www.ebay.co.uk/itm/DRG-010632B-Labfacility-...

However, when I connect the controller to the mains, the display immediately keeps flashing as follows:
- PV - '635.7' / 'orAL'
- SV - 'A 0' / 'HiAL' / 'oHAL' / 'orAL'.
Whatever setting I use in the controller SET menu it keeps displaying/flashing the same thing (as above) after leaving SET menu.

I would like to set up this controller to maintain temperature 88-90 degC with ON/OFF mode, of the solution. The heating initially should start from 20degC.

I have the basic manual (I do not have the original paper one which came with the controller).
http://www.sestos-hk.com/english/download/d1s-en.p...

I am not sure know now whether the values I set in menu are correct:
- Absolute-value upper-limit - 90degC,
- Absolute-value lower-limit - 88degC,
- Upper limit(deviation)- 1degC,
- Lower limit(deviation)- 1degC,
- Hysteresis - 0.3(?)
- Control output - 0 (ON/OFF),
- M50 Integral- ? (is it needed for ON/OFF mode?)
- Differential - ? (is it needed for ON/OFF mode?)
- Hysteresis time - ? (is it needed for ON/OFF mode?)
- Control period - ? (is it needed for ON/OFF mode?)
- Input sensor - 21 (PT100 probe)
- Decimal point position - ?
- input lower limit display -5degC,
- input upper limit display - 95degC.
- Sensor calibration - ?
- Output method - ?
- Output lower limit - ?
- Output upper limit - ?
- Alarm function - ?
- System function - 2 (heater)
- Addr - 1
- Baud - 9600
- Input digital filter - ?
- Run mode - 1(?) (automatic)
- loc - 40
- EP1-Ep8 - none

P.S. I also tried to swap the cables of the probe in the controller but no effect.

Please help.

Regards







RE: Set-up of Sestos PID controller

Are you running it in auto-adjustment mode? If so, it may need a few hours before it's fully configured and stops complaining.

Dan - Owner
http://www.Hi-TecDesigns.com

RE: Set-up of Sestos PID controller

(OP)
@acGyverS2000
Thank you for your reply.
I have also tried 'run mode' manual (0) but regardless what I do, once I am out of SET menu display keeps flashing:
- PV - '635.7' / 'orAL'
- SV - 'A 0' / 'HiAL' / 'oHAL' / 'orAL'.

RE: Set-up of Sestos PID controller

Some observations

A reading of 635.7 is likely Deg C, which is likely the burn-out reading for a miswired 3 wire RTD.

A 3 wire RTD can be wired in 6 different ways, only two of which will work. The resistance has to go beteween terminals 3 and 4 with the common wires on 4 and 5. Which common wire goes to 4 or 5 doesn't matter, but the other side of the resistor has to go to terminal 3.

Get it reading the correct PV (temperature) first, everything else is secondary.

Your control setpoint (SV) is presumably not your alarm setpoint.

The absolute values you state are alarm setpoints, which probably not your control setpoint (SV).

dF Hysteresis is likely the difference between the ON and OFF trip points around your setpoint, 0.3 Deg C. That's pretty tight for a relay output heater, the relay is likely to cycle very often, once you get it running as a controller.

An upper display limit of 95C for a setpoint of 90C is a hopeful touch. Any particular reason you didn't make the limits a conventional 0-100 Deg C?

I would think that when you select ON-OFF for the control output (CtrL), that Output Method (OP1) would disappear. Time duty doesn't make any sense for ON-OFF control. It isn't clear to me what "AL1 together with OUT" is

Run mode = automatic is OK

Manual mode is probably asking what the fixed output value should be. Manual mode is not what you bought a controller for.

RE: Set-up of Sestos PID controller

(OP)
@danw2
Thank you for your reply.
You were right I missed the common wire (I did not know I need it).
I bridged 4 and 5. I connected 1 red wire to 5 and 1 white wire to 3.
(there are four wires of probe- 2 white and 2 red)
The sensor seems to read the temperature correctly now.
However, the question whether I connected 'right' pair of 1 white and 1 red wires to the sensor is unknown, I do not have a multimeter.

"An upper display limit of 95C for a setpoint of 90C is a hopeful touch. Any particular reason you didn't make the limits a conventional 0-100 Deg C?"
No particular reason. I changed it back to 0-100degC.

If you do not mind I would have another question.
I use following DC-DC SSR (for Sestos controller):
http://docs-asia.electrocomponents.com/webdocs/145...

When I connect my electric circuit to mains (the circuit is - 230AC-12VDC/42A power converter, SSR, Sestos controller, 12V-25A 300W heater, PT100 immersion probe) then the heater is immediatelly powered.
I expected that in order to power the heater, Sestos must send a signal to SSR, then SSR starts 'powering' the heater, what would be noted by a red LED ON at SSR. Nevertheless, the heater is always ON, the LED is always OFF.
I checked whether the SSR is normally opened or closed. I did not find such info. I can only assume that it is normally opened.
I assume that even if the Sestos is not properly setup and if SSR is normally opened, the heater cannot be powered, unless I have miswiring.

P.S.
My circuit is:
FROM PSU- 12VDC "-" goes directly to heater.
FROM PSU- 12VDC "+" goes to '1' in SSR (LOAD side of SSR which is 40A 100VDC).
FROM PSU- 230VAC goes to 9 (L) and 10 (N) in controller.
FROM SSR- 12VDC "+" goes from '2' in SSR (LOAD side of SSR which is 40A 100VDC) to the heater.
FROM CONTROLLER- 12VDC "+" goes from '8' to '3' in SSR (INPUT side of SSR which is 4-32VDC)
FROM CONTROLLER- 12VDC "-" goes from '6' to '4' in SSR (INPUT side of SSR which is 4-32VDC)
As earlier: foe PT100 probe I bridged 4 and 5 in controller. I connected 1 red wire to 5 and 1 white wire to 3.

Thanks.

RE: Set-up of Sestos PID controller

(OP)
Update to my last input.

I have simplified my electric circuit for simple test to verify whether controller actually controls the powering of the heater.

My simplified electric circuit consisted of PSU, DC-DC SSR, 12VDC heater (sensor and probe were disconected from them but I could read the actual temperature of solution on the sensor).
What I have found out was that in this simplified circuit the heater was still powered!

The details of my simplified circuit were (there were only 3 cables used):
1 cable between PSU-heater - 12VDC "-"
1 cable between PSU-SSR - 12VDC "+" goes to '1' in SSR (LOAD side of SSR which is 40A 100VDC).
1 cable between SSR-heater - 12VDC "+" goes from '2' in SSR (LOAD side of SSR which is 40A 100VDC) to the heater.

Again '3' and '4' connections in SSR remained unwired.
There is only one explanation- this SSR is normally closed, which is not the case when I check in the web.
I am confused.

RE: Set-up of Sestos PID controller

The PLUS (+) from the power supply goes to the SSR terminal 2!! Your heater is to be hooked to terminal 1.

You describe a backwards hook-up. Hopefully you haven't destroyed the SSR.

Also keep in mind with SSRs, they often leak current. This one states it does. The amount it leaks is inconsequential to heating but can drive you crazy when you use a voltmeter that will show what looks like the relay being ON when it is in-fact off and just 'leaking'. You should confine your determination of the SSR being ON or OFF by whether the heater is physically heating or not heating - not a voltage measurement.

Lastly, since you appear a newbie to all this I remind you that SSRs dissipate heat and are not like normal relays. This means you will burn them up if they are not properly heat-sinked so they can rid themselves of their heat of inefficiency. What current does your 12V heater draw or what is its resistance? From this we can determine the class of heat sinking you need to prevent the relay from promptly burning out.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Set-up of Sestos PID controller

(OP)
@itsmoked
Thank you for your reply.
I have switched the cables between termainals 1 and 2 in SSR. The circuit works very good now. Thank you.

Please allow me to ask about one more thing.
I need to slow down the heating rate of the solution.
I would like to use the timer H3RN-1-B (I have it):
http://www.valin.com/sites/default/files/asset/doc...

My electric circuit is 12VDC.
Rated supply voltage for this timer is: 24 VAC (50/60 Hz); 12, 24 VDC
However, in regards to the rated power supply, the timer manual states that (at top and bottom of page 2 in linked manual):
- cULus (Listing): Applicable when an OMRON P2RF-@-PU Socket is used.
- cURus (Recognition): Applicable when any other socket is used.
My understanding is that in order to power this timer with 12VDC I need to plug it in into the OMRON P2RF-@-PU socket ?

Also I am looking for a possibility of slowing down the heating rate with change of the Sestos PID controller settings.
I have read that increasing of the 'P' value can do the work (to some extend).
Would there be any other PID setting that could be changed to slow heating rate?

Thanks.

RE: Set-up of Sestos PID controller

ON/OFF control with that controller and an SSR is... bizarre. Look around the web a little and learn what PID can do for you. Then switch to PID and you can probably stop worrying about "too fast".

Using ON/OFF is like using your sophisticated temp controller in 'rocks and string' mode!

Why pray-tell are you using the timer at all?

Keith Cress
kcress - http://www.flaminsystems.com

RE: Set-up of Sestos PID controller

(OP)
@itsmoked
Thank you for your reply.
I did not update my post in regards to use of ON/OFF and PID options.
I have already switched to PID.
I think that I will try first changing the value of output limiter (from 100% say to 50% first).
Hopefully, this solution will ok.

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